Ammunition



Patented May 10, 1938 UNITED STATES PATEN OFFICE AMMUNITION No Drawing. Application April 25, 1934, Serial No. 722,240

4 Claims.

This invention relates to priming mixtures for ammunition, and contemplates the use of ingredients whichare substantially double compounds, including in a single molecule both an .oxidizer and a fuel.

The usual ammunition priming mixture in reacting ingredients the more rapid would be their combustion, but actually separate reacting ingredients cannot be granulated below a certain fineness, say 150 or 200 mesh. One reason for this is that the finer particles do not set up sufficient friction to initiate the reaction.

The ideal priming mixture is one in which the reacting ingredients lie in close proximity to each other in the same crystal. In the past some efforts have been made to produce priming compositions consisting solely of such crystals, but the product has invariably failed to satisfy other requirements of successful priming.

The present invention contemplates'th use, in a priming mixture including a combustioninitiator and/or a frictionator, of a material in which an oxidizer and a fuel are both present in a single crystal. This material is a reaction product of lead nitrate and lead hypophosphite. Lead nitrate is a compound which is rich in oxygen and yields its oxygen with considerable facility at a comparatively low temperature. Lead hypophosphite is deficient in oxygen. When these substances are brought together in the presence of moisture a reaction takes place which results in a compound apparently having the composition Pb(NO3)2'Pb(HzPO2)2. This compound will be called lead nitrato-hypophosphite. While lead nitrato-hypophosphite alone is quite sensitive to blow, its explosion cannot be depended upon to ignite powder. Its deficiency appears to be due to the fact that its decomposition is accompanied by only a comparatively short flame, and the evolution of a comparatively small volume of gas. For these reasons, it has been found necessary to include in priming mixtures madetherefrom an explosive combustion initiating ingredient,suchas normal or basic lead styphnate, basic lead picrate, normal or basic lead azide, diazodinitrophenol, mercury fulminate, tetrazole derivatives and their salts,the salts of diand tri-nitro benzoic,phthalic and salicylic acids. Other oxidizingingredients, such as potassium chlorate, barium nitrate and/or lead peroxide, and other fuel ingredients, such as lead sulphocyanate, antimony sulphide and/or calcium silicide, may also be included.

In preparing the mixture, the lead nitrate and lead hypophosphite are preferably added separately, the reaction between them occurring in the mixture. The several ingredients are brought together and thoroughly mixed while dry, the mixture is then moistened and mixing is continued until the reaction between lead nitrate and lead hypophosphite is complete.

A typical mixture which has been found to be especially useful in brass rimfire shells comprises lead styphnate, lead hypophosphite, lead nitrate, lead sulphocyanate, and glass, in substantially the following proportions:

Preferred,

Per cent per cent Lead styphnate 20 to 40 33 Lead hypophosphite 8 to 30 10 Lead nitrate 10 to 12 Lead sulphocyanate 6to 12 10 Glass 12 to 25 20 Per cent Basic lead picrate 30 Lead hypophosphite 12 Lead nitrate 33 Glass 25 Other explosives or combinations of explosives may likewise be used, as above-indicated. Barium nitrate has been added in amounts up to 40%, yielding mixtures which for some purposes are very desirable. Lead peroxide has-likewise been found useful as a supplemental oxidizing ingredient. The presence of lead sulphocyanate is unnecessary, many successful mixtures having been made without' any supplemental fuel.

The foregoing are merely typical of the wide variety of mixtures coming within the scope of the invention, the invention being directed br'oadly to mixtures utilizing an explosive ingredient in conjunction with lead nitrato-hypophosphite, and the appended claims are to be broadly construed.

What is claimed is:

1. A priming mixturecontaining lead nitratohypophosphite and an explosive ingredient se- Eected from the class consisting of lead styphnate, basic lead styphnate, lead azide, basic lead azide, basic lead picrate, diazodinitrophenol, mercury fulminate, tetrazole derivatives and their salts, the salts of diand tri-nitro benzoic, phthalic and salicylic acids.

2. A priming mixture containing lead nitrate: hypophosphite, lead styphnate, and a supplemental oxidizing ingredient.

3. A priming mixture containing lead nitratohypophosphite, basic lead styphnate, and.a supplemental oxidizing ingredient.

4. A priming mixture containing lead nitratohypophosphite, basic lead picrate, and a supplemental oxidizing ingredient.

WILLI BRUN. {AMES E. BURNS. 

